Nonlinear Photonic Diode Behavior in Energy-Graded Core–Shell Quantum Well Semiconductor Rod

Future technologies require faster data transfer and processing with lower loss. A photonic diode could be an attractive alternative to the present Si-based electronic diode for rapid optical signal processing and communication. Here, we report highly asymmetric photonic diode behavior with low scattering loss, from tapered core–shell quantum well semiconductor rods that were fabricated to have a large gradient in their bandgap energy along their growth direction. Local laser illumination of the core–shell quantum well rods yielded a huge contrast in light output intensities from opposite ends of the rod.